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Synonyms

insoluble

American  
[in-sol-yuh-buhl] / ɪnˈsɒl yə bəl /

adjective

  1. incapable of being dissolved.

    insoluble salts.

  2. incapable of being solved or explained.

    an insoluble problem.


insoluble British  
/ ɪnˈsɒljʊbəl /

adjective

  1. incapable of being dissolved; incapable of forming a solution, esp in water

  2. incapable of being solved

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

insoluble Scientific  
/ ĭn-sŏlyə-bəl /
  1. Not capable of being fully dissolved. Fats and oils are insoluble in water.


Other Word Forms

  • insolubility noun
  • insolubleness noun
  • insolubly adverb
  • semi-insoluble adjective

Etymology

Origin of insoluble

1350–1400; < Latin insolūbilis; replacing Middle English insolible < Middle French insoluble < L. See in- 3, soluble

Explanation

Let a bottle of salad dressing stand on the table for a few hours and you will notice that it has separated into layers. That's because oil is insoluble or is not capable of being dissolved. Insoluble comes from the Latin insolubilis meaning "that cannot be loosened." When a substance is insoluble, it cannot be dissolved or loosened in water. Similarly, a situation that is insoluble has no hope of being solved. When a marriage is beyond repair and cannot be fixed, it is insoluble.

Keep Reading on Vocabulary.com

Vocabulary lists containing insoluble

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Purple, savoy and green cabbage are also high in insoluble fiber, which Beitchman says is “the broom of the digestive system,” allowing waste to pass through more easily.

From Salon • Feb. 21, 2026

But if a problem is insoluble, it’s not a problem anymore; it’s just the way things are.

From Salon • Dec. 31, 2024

Unfortunately, this feeling is often associated with insoluble dietary fibers.

From Science Daily • Nov. 20, 2024

To date, approaches to treatments for Alzheimer's disease have not addressed the contribution of protein insolubility as a general phenomenon, instead focusing on one or two insoluble proteins.

From Science Daily • May 16, 2024

Susan Calvin burst into body-racking gusts of wild laughter, “not dead—merely insane. I confronted him with the insoluble dilemma, and he broke down. You can scrap him now—because he’ll never speak again.”

From "I, Robot" by Isaac Asimov